Fourteen patients have now been examined for systemic mastocytosis. Seven of these patients were found to have systemic mastocytosis, four had urticaria pigmentosa and three were diagnosed as having idiopathic recurrent anaphylaxis. Those with systemic mastocytosis were found to have an abnormal pre-beta lipoprotein. Also found was an increased incidence of cardiac disorders including mitral value prolapse. Bone disease was reflected in abnormal bone scans low hydroxyprolines, and elevated Gla protein. Six patients with systemic mastocytosis are entered into a double-blind single crossover study comparing the therapeutic benefit of cromolyn sodium vs. chlorpheniramine and cimetadine.